1. Field of the Invention
This invention relates to phonographs, and particularly to an improved drive control mechanism for the turntable of a phonograph.
It is desirable in phonographs to provide an improved drive control mechanism having an off position in which the drive motor is turned off and a driven puck is disengaged from the drive shaft and turntable, a 331/3 rpm (revolutions per minute) position in which the puck engages one part of the drive shaft and the turntable for driving same at 331/3 rpm, and a 45 rpm position in which the puck engages a different part of the drive shaft and the turntable for driving same at 45 rpm. This is achieved by a drive shaft having drive portions of different diameter, a rotatable puck interposed between the drive portions and turntable for drivingly coupling and uncoupling them, and linkage means for coupling the puck to a control lever which is movable between the off, 331/3 rpm and 45 rpm positions.
2. Description of the Prior Art
Drive control mechanisms for the turntable of a phonograph are known. However, such drive control mechanisms normally have a rotatable puck in constant driving engagement with the turntable whether the drive motor is turned on or off. When the drive motor is turned on, the turntable is driven at a selected speed. A problem with this type of drive control mechanism is that the puck, being in substantially constant pressure engagement with the drive shaft in the off position, develops a flattened surface portion which interferes with driving the turntable at a constant rotational velocity.